"California could be the golden key to winning the Republican nomination," said Mesa College political science professor Carl Luna.California's June 5 contest will be the next to last Republican primary, and with candidates Mitt Romney and Rick Santorum going back and forth, the delegate math could add up to a win for the state and its 172 delegates."When it comes to politics, size of the delegate count matters and California is the biggest prize," said Luna.Another big factor: any candidate could grab a large share of the delegates.In California, the delegates will be awarded in winner-take-all fashion by congressional district.In 2008, even though John McCain defeated Romney by 8 percent, he ended up with almost all the delegates.Locally, McCain beat Romney in 4 of 5 congressional districts.If Romney wins the state this time, it could push him across the finish line. A mediocre results could force the nomination into the Republican National Convention, where anything could happen.Either way, political experts say California will likely be critical. It could mean millions of dollars spent in media advertising.Republican Party of San Diego Chairman Tony Krvaric said even a few weeks ago, it was hard to believe California's vote would have mattered."We're on new ground, but it's extremely exciting. Right now, there's no much organization, but if it looks like it's going to go to California, you are going to see a lot of activity here," Krvaric told 10News.Republican leaders also point to the benefits of the political spotlight."We want the presidential candidates to pay attention to California issues," said Krvaric.Romney, who is considered more moderate on social issues, has polled well in California, but his lead over Santorum is shrinking.Still, many say Romney has an undeniable edge."California is a very expensive media state. Romney will 'carpet bomb' the state with money. That could be the deciding factor," said Luna.